Hi Jerry, one thing that could happen is that for some reason your server machine ran out of memory and in an attempt to keep the OS running it just killed the biggest memory user which just might be your Tomcat process. We had that happen to some development systems where the Tomcat "vanished" after 3 month uptime, because it was killed from the outside due to memory pressure.
But your request does not provide enough info to tell. What I would do is turn on Java GC logging and see how the activity goes. Or use something like "visualvm". Add "-XX:+HeapDumpOnOutOfMemoryError" to the Java options. Look at the dump to see whether you have a leak in some rarely exercised code path. Cheers Martin On Tue, Apr 13, 2021 at 1:12 AM Jerry Malcolm <techst...@malcolms.com> wrote: > I'm getting TC crashes (ver 8.5) with "out of memory" errors. I > understand heap space and the parameters to set it. But I need a bit of > help with "out of memory", not "out of heap space". This is running in > an EC2 on AWS. It's a development server, so activity is minimal > compared to production. We also are running it on a smaller EC2 which > is likely contributing to the problem. But interestingly the last crash > happened in the middle of the night. The last request came in 15 > minutes prior to the crash, and it was some php intrusion attempt URL > that returned 404. Crashes don't happen often. A couple of servers have > failed once or twice a week. And this is the first time the dev server > crashed. But I still really need to get a handle on it. > > We have a pretty large max heap space configured. Does this problem > have something to do with specifying a heap space larger than TC can > allocate with physical memory? I figured there was still the option of > virtual memory and swapping if it ran out of physical memory. > > I need to learn more and tuning the memory usage. Is there some formula > that tells me the max heap space given a certain size of physical > memory? Or is there something else I'm totally missing about memory > configuration? > > Thanks. > > Jerry > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > > -- ------------------------------------------------------ Martin Knoblauch email: k n o b i AT knobisoft DOT de www: http://www.knobisoft.de
